1. Field of the Invention
The present invention relates to a white balance adjustment which is carried out in a digital camera for example
2. Description of the Related Art
Digital cameras are used to photograph objects which are illuminated by various light sources having different color temperatures, for example: sunshine, fluorescent lamps, incandescent lamps, and so on. The color tone of the photographed object image is affected by the color temperature of the light source, therefore, the color tone of the photographed object image is sometimes different from that of the object.
For eliminating the difference in the color tone, conventionally a white balance of the photographed object image is adjusted. The white balance adjustment is usually carried out based on color balance information (white balance information), which is generated automatically or manually.
It is known that the color balance information can be generated manually based on color temperature information that is input by the user as shown in Japanese Unexamined Patent Publication (KOKAI) NO. H11-355784. However, with this method, the user has to grasp the color temperature of all the light sources in advance to input the color temperature information. Further, the object in sometimes illuminated by a combination of a plurality of light sources. In this case, it is difficult for a user to identify the color temperature of the combination, even if the user grasps the color temperature of all the light sources.
A method for manually generating color balance information is known whereby an object having achromatic color (for example the white or gray paper) is displayed as the display image in the whole display field, and then the color balance information is generated using all the color data of the object image. In this method, precise color balance information can be generated even if the object is illuminated by a plurality of light sources. However, it is difficult to photograph an object having achromatic color, using the whole display field.